Verdicts

Every extraction carries a verdict. The model transcribes; deterministic code decides. Nothing about the verdict is the model’s opinion.

PASS The traverse closes and the computed area corroborates the area the document states. Both checks agree.

REVIEW Something needs human eyes, and the reasons say what. A misclosure past the threshold, an area that disagrees with the stated one, a course the extractor was unsure of, or a unit that could mean two things.

FAIL Not traversable. A call with no bearing, a unit the engine does not recognise, or a description that never located itself. The failing call is quoted.

The two checks

These are the checks for a description that carries courses. An aliquot call has none, and is judged by the rules further down.

Closure, at 1:5,000. The traverse is recomputed from the extracted courses and walked back to its start. The gap between where it ends and where it began, over the perimeter, is the closure ratio.

Stated area, within 2%. The area the recomputed boundary encloses is compared against the acreage the document itself states, in the unit the document used.

They are independent on purpose. An extraction can close beautifully and enclose the wrong area, which is what a transposed digit looks like.

Why a REVIEW is worth as much as a PASS

The product is not the polygon, it is knowing which polygons to trust. A tool that quietly closes a failing traverse produces a drawing nobody downstream can question. A REVIEW that names its misclosure and quotes the suspect courses is the thing that was bought.

Aliquot descriptions are judged on area alone

“The SW¼ of the NE¼ of Section 14, T18S R19E” states no courses, so there is no traverse to recompute and closure means nothing. The geometry comes from BLM’s survey fabric rather than from the deed, and the deed’s own stated acreage is the only independent thing left to check it against. That is why an aliquot tract behaves differently from a metes-and-bounds one, and why it is held at REVIEW more readily.

Any of these holds it at REVIEW:

reason	what it means
no stated acreage	Area is the only corroboration available, so an aliquot tract that states none cannot PASS however clean everything else looks.
computed area is more than 10% off the nominal area	The nominal area is what that chain of parts encloses in a regular section. A wider gap means either an irregular section or a chain read wrong.
computed area is more than 2% off the stated acreage	The same tolerance a metes-and-bounds tract gets.
an exception or qualifier that quarter/half arithmetic cannot express	“The North 158.50 feet of the South 730 feet of the SW¼ of the NE¼” describes a strip, and a strip is not an aliquot part. The verdict says so instead of drawing the whole quarter-quarter and calling it the parcel.
a government lot	Lot geometry needs the fabric’s second division, which this version does not compute.
an ambiguous principal meridian	The township, range and section exist under more than one meridian and the deed names none of them.

FAIL is kept for a chain the fabric cannot resolve at all.

What the arithmetic cannot see

Closure and stated area can both be satisfied by a boundary that is mirrored, or that has a quadrant transposed, because those errors are symmetric. A reader can see it; the arithmetic cannot. That is why every certificate draws the tract.